New Development of the Multiple Strata Plasticity Model

Abstract

The multiple strata plasticity model, which was presented in the previous paper by introducing the tensor Q expressing the activating state of slip systems in the polycrystalline metal, has been developed with a new internal state factor B₅. This factor B₅ denotes the ratio of the grains with activating slip systems greater than five to the total grains. The variation features of B₅ and Q can be computationally evaluated with a virtual polycrystalline specimen. The microstructure state, such as dislocation density can be reflected in the internal structure variable A in this model. The relationship between B₅ and A has been examined on the tensile flow curve of pure copper. As a result, a simple formula connecting A with B₅ was determined. Moreover, it has been clarified that this formula is applicable for describing the plastic deformations under other proportional loadings.